Characteristics of beta reference radiation fields at the Facility of Radiation Standards (FRS), JAEA for their practical applications in beta dosimetry

Yoshitomi, Hiroshi   ; Kowatari, Munehiko; Suzuki, Takashi

The Facility of Radiation Standards (FRS) in the Japan Atomic Energy Agency (JAEA) provides beta-ray calibration fields for the customers to calibrate dosemeters. Two different types of beta-ray irradiation systems, so called BSS2 and JBS, have been installed and operated in the FRS. They have quite different types of the beta-ray radiation sources, which might be attributed to variations in dosimetric quantities. Variations in these quantities would affect the calibration factor of a dosemeter. A comparison of dosimetric quantities for beta reference radiation fields of both beta-ray irradiation systems was made, in order to investigate how these quantities differ between them and how much differences affect calibration results. With regard to the depth dose curve which is one of the key dosimetric quantities, it was found that they showed different profiles between both systems reflecting their characteristics. This implies that the difference between two systems might affect the calibration of dosemeters, especially one with more than 400 mg/cm thickness or one made of high-Z materials for Sr/Y field.